Data race in new discovery test

[grobie]

The new discovery test setup is not concurrancy safe. The atomic package must be used for all reads, not only for writing values.

==================
WARNING: DATA RACE
Read at 0x00c420453478 by goroutine 42:
  github.com/prometheus/prometheus/discovery.TestTargetSetThrottlesTheSyncCalls()
      /home/grobie/code/go/src/github.com/prometheus/prometheus/discovery/discovery_test.go:503 +0x6765
  testing.tRunner()
      /usr/lib/go/src/testing/testing.go:746 +0x16c

Previous write at 0x00c420453478 by goroutine 44:
  sync/atomic.AddInt32()
      /usr/lib/go/src/runtime/race_amd64.s:269 +0xb
  github.com/prometheus/prometheus/discovery.mockTargetProvider.Run()
      /home/grobie/code/go/src/github.com/prometheus/prometheus/discovery/discovery_test.go:1034 +0x40
  github.com/prometheus/prometheus/discovery.(*mockTargetProvider).Run()
      <autogenerated>:1 +0xa2

Goroutine 42 (running) created at:
  testing.(*T).Run()
      /usr/lib/go/src/testing/testing.go:789 +0x568
  testing.runTests.func1()
      /usr/lib/go/src/testing/testing.go:1004 +0xa7
  testing.tRunner()
      /usr/lib/go/src/testing/testing.go:746 +0x16c
  testing.runTests()
      /usr/lib/go/src/testing/testing.go:1002 +0x521
  testing.(*M).Run()
      /usr/lib/go/src/testing/testing.go:921 +0x206
  main.main()
      github.com/prometheus/prometheus/discovery/_test/_testmain.go:50 +0x1d3

Goroutine 44 (finished) created at:
  github.com/prometheus/prometheus/discovery.(*TargetSet).updateProviders()
      /home/grobie/code/go/src/github.com/prometheus/prometheus/discovery/discovery.go:250 +0x3aa
  github.com/prometheus/prometheus/discovery.(*TargetSet).Run()
      /home/grobie/code/go/src/github.com/prometheus/prometheus/discovery/discovery.go:199 +0x3bf
==================

@grandbora Can you fix this please? You can check for the existance of data races with go test -race ./discovery/....

[grandbora]

On it.

[grandbora]

#3458 fixes this issue. cc @grobie @brian-brazil

[AndreaGiardini]

I think this issue can be closed

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.